lst/lstV2/server/globalUtils/scannerConnect.ts

/**
 * Using this to make a scanner connection to the server.
 */

import net from "net";

interface QueuedCommand {
	command: string;
	resolve: (value: string) => void;
	reject: (reason?: any) => void;
	timeout: NodeJS.Timeout;
}

const STX = "\x02";
const ETX = "\x03";

// const prodIP = process.env.SERVER_IP as string;
// const prodPort = parseInt(process.env.SCANNER_PORT || "50000", 10);
// const scannerID = `${process.env.SCANNER_ID}@`;
//const scannerCommand = "AlplaPRODcmd00000042#000028547"; // top of the picksheet

export class ScannerClient {
	private socket = new net.Socket();
	private connected = false;

	private queue: QueuedCommand[] = [];
	private processing = false;

	private incomingBuffer = "";

	constructor(
		private host: string,
		private port: number,
		private scannerId: string,
	) {
		this.initialize();
	}

	private initialize() {
		if (!this.host || !this.port) {
			console.log("Host or port is missing");
			return;
		}
		this.socket.connect(this.port, this.host, () => {
			console.info("Connected to scanner");
			this.connected = true;
		});

		this.socket.on("data", (data) => this.handleData(data));

		this.socket.on("close", () => {
			console.log("Scanner connection closed");
			this.connected = false;
		});

		this.socket.on("error", (err) => {
			console.error("Scanner error:", err);
		});
	}

	// ✅ Public method you use
	public scan(command: string): Promise<string> {
		if (!this.connected) {
			return Promise.reject("Scanner not connected");
		}

		return new Promise((resolve, reject) => {
			const timeout = setTimeout(() => {
				this.processing = false;
				reject("Scanner timeout");
				this.processQueue();
			}, 5000); // 5s safety timeout

			this.queue.push({
				command,
				resolve,
				reject,
				timeout,
			});

			this.processQueue();
		});
	}

	// ✅ Ensures strict FIFO processing
	private processQueue() {
		if (this.processing) return;
		if (this.queue.length === 0) return;

		this.processing = true;

		const current = this.queue[0];
		const message = Buffer.from(
			`${STX}${this.scannerId}${current.command}${ETX}`,
			"ascii",
		);

		this.socket.write(message);
	}

	// ✅ Handles full STX/ETX framed responses
	private handleData(data: Buffer) {
		console.log(
			"ASCII:",
			data
				.toString("ascii")
				.replace(/\x00/g, "") // remove null bytes
				.replace(/\x1B\[[0-9;?]*[A-Za-z]/g, "") // remove ANSI escape codes
				.trim(),
		);

		const current = this.queue.shift();
		if (current) {
			clearTimeout(current.timeout);
			current.resolve(data.toString("ascii"));
		}

		this.processing = false;
		this.processQueue();
	}
}

export const scanner = new ScannerClient(
	process.env.SERVER_IP!,
	parseInt(process.env.SCANNER_PORT!, 10),
	`${process.env.SCANNER_ID}@`,
);

// export const connectToScanner = () => {
// 	if (!process.env.SERVER_IP || !process.env.SCANNER_PORT) {
// 		return {
// 			success: false,
// 			message: "Missing ServerIP or ServerPort",
// 		};
// 	}

// 	scanner.connect(prodPort, prodIP, () => {
// 		console.log("Connected to scanner");
// 		connected = true;
// 	});
// };

// export const scan = async (command: string) => {
// 	if (!connected) {
// 		return {
// 			success: false,
// 			message: "Scanner is not connected, please contact admin",
// 		};
// 	}
// 	if (inScanCommand) {
// 		bufferCommands.push({ timeStamp: new Date(Date.now()), command: command });
// 	}

// 	// we are going to set to scanning
// 	inScanCommand = true;

// 	const message = Buffer.from(`${STX}${scannerID}${command}${ETX}`, "ascii");
// 	scanner.write(message);
// 	await new Promise((resolve) => setTimeout(resolve, 750));

// 	inScanCommand = false;

// 	if (bufferCommands.length > 0) {
// 		await scan(bufferCommands[0].command);
// 		bufferCommands.shift();
// 	}

// 	return {
// 		success: true,
// 		message: "Scan completed",
// 	};
// };

// scanner.on("data", async (data) => {
// 	console.log(
// 		"Response:",
// 		data
// 			.toString("ascii")
// 			.replace(/\x00/g, "") // remove null bytes
// 			.replace(/\x1B\[[0-9;?]*[A-Za-z]/g, "") // remove ANSI escape codes
// 			.trim(),
// 	);
// });

// scanner.on("close", () => {
// 	console.log("Connection closed");
// });

// scanner.on("error", (err) => {
// 	console.error("Scanner error:", err);
// });